Method for production of a reaction rod for vehicles and said reaction rod

ABSTRACT

A method of manufacturing a reaction rod for use in connecting a chassis ( 21 ) of a vehicle with a wheel axle housing ( 22 ) of the vehicle. The reaction rod comprises a rod ( 1 ) with two end portions, two housings ( 2,3 ), each of which can be securely connected with its rod end portion, and two attachments pieces ( 8,9 ), each of which extends through its passage ( 4,5 ) of the housings ( 2,3 ). The attachment pieces ( 8,9 ) are arranged to be attached to the chassis ( 21 ) and the wheel axle housing ( 22 ) respectively. The distance between reference points ( 16,17 ) of the respective attachment pieces ( 8,9 ) establishes a functional length (F) of the reaction rod. The method comprises the steps of manufacturing the housings by stamping and bending of a plate, manufacturing the attachment pieces ( 8,9 ) with a clearance relative to the passages ( 4,5 ) inserting the attachment pieces ( 8,9 ) in the respective passages ( 4,5 ), mounting the attachment pieces ( 8,9 ) in a jig, the distance between the reference points ( 16,19 ) corresponding to the functional length (F), and attaching the housings ( 2,3 ) to the rod ( 1 ). A reaction rod with housing manufactured from a plate.

The invention relates to a method for manufacturing a reaction rod forconnecting a chassis of a vehicle with a wheel axle housing of thevehicle, as indicated in the introduction to claim 1.

From EP 0 684 404 a reaction rod is known where the attachment piecesare provided with press fit relative to the passages. Inserting theattachment pieces with force fit in the passages results in tangentialstresses in the housings. During operation of such a reaction rod,exceptionally high stress concentrations will occur at the portion ofthe housings located at the transition between the passages and the pinsdue to the press fit of the attachment pieces. The houses are thereforeforged and the other connecting portions of the housings comprise solidpins arranged to be inserted in tubular end portions of the rod. Thisresults in the reaction rod being heavy.

From DE 4 132 779 a reaction rod is known with a favourable weight tostrength ratio.

To manufacture the known reaction rods, the attachment pieces and anassembly comprising the rod and the houses are fabricated separately.Care must be taken during this process to ensure that each of thesecomponents is manufactured with tolerances that ensure that aspecifically defined distance between reference points or length of thefinished reaction rod, a so-called functional length, has a value thatis within a desired tolerance. This tolerance may typically be, e.g.±0.5 mm. The reason for this is that when two reaction rods areemployed, for example, it must be ensured that the wheel axle housinghas a desired orientation relative to the chassis.

Since three components with tolerances have to be fabricated for eachreaction rod, viz. a rod/housing assembly and two attachment pieces, andthe tolerance for the functional length is obtained by an addition ofthe components' length tolerances, this method of manufacture isexpensive. Furthermore, there is a risk of obtaining reaction rods withan incorrect functional length on account of the addition of the manytolerances, the risk that these tolerances may deviate from the correctvalue increasing with the number of components manufactured withtolerances.

In order to try to avoid having to reject reaction rods with incorrectfunctional length, after manufacture the reaction rods may be measuredand classified according to length, since the use of reaction rodswithin the same length classification ensures the above-mentioned,desired orientation of the wheel axle housing in the chassis. To measureand classify the reaction rods in this manner is time-consuming, and inaddition a separate storage place has to be provided for each lengthclassification.

A second option is to place thin metal distance pieces or shims betweenthe reaction rod and the chassis or wheel axle housing for compensationof an incorrect functional length. A disadvantage of this method is thata storage place must be made and provided for distance pieces, and themeasurement, choice and adaptation of distance pieces during a reactionrod assembly is time-consuming.

Furthermore, from the international application PCT/DE99/01274 it isknown that the length of the reaction rods may be adjustable. Eventhough the manufacture of the reaction rod's components according totolerance measurements is hereby avoided, the measurement and adjustmentof such reaction rods is time-consuming and the reaction rods arecomplicated and expensive.

The object of the invention is to provide a light-weight reaction rodwhich is manufactured by a method that is not encumbered by theabove-mentioned drawbacks.

The characteristic of the invention will be apparent from thecharacterising features indicated in the claims.

The invention will now be described in greater detail with reference tothe drawing which illustrates an embodiment of a reaction rod which hasbeen manufactured by means of the method according to the invention.

FIG. 1 is a perspective view of a reaction rod.

FIG. 2 is a perspective view of the end portion of the reaction rodindicated by A in FIG. 1, where an attachment piece has been inserted ina passage of a housing of the reaction rod.

FIG. 3 is a perspective view of an attachment piece like thatillustrated in FIG. 2.

FIG. 4 is a perspective view of the reaction rod illustrated in FIG. 2,but where the attachment piece has been removed from the passage.

FIG. 5 is a schematic perspective view of a first jig wherein endportions of a reaction rod are secured, for use in a first variant of amethod for manufacturing a reaction rod according to the invention.

FIG. 6 is a perspective view of a second jig for use during theexecution of a second variant of a method according to the invention.

As can be seen in FIG. 1, the reaction rod comprises a central portionor a rod 1 and two heads or housings 2,3, which are securely connectedto the rod 1 by respective end portions of the rod 1. The rod 1 may havea circular cross section and a longitudinal axis 6. Each housing 2,3 hasa through-going passage 4,5 whose longitudinal axis 7 extends at anangle, e.g. 90° relative to the rod's longitudinal axis 6, this anglebeing dependent on how the reaction rod extends relative to the chassisand the wheel axle housing. The passages are preferably cylindrical andcircular in cross section.

The reaction rod's end portions are substantially identical, and what isdescribed below with reference to one end portion also applies to thesecond end portion.

As also illustrated in FIGS. 2 and 3, an attachment piece 8,9 isinserted in each passage 4,5.

At its central portion, each attachment piece 8,9 may comprise an outer,tubular casing 11 and between this casing 11 and a core 12 extendingthrough the casing 11, there is mounted a rubber element 13, which issecurely connected to the casing 11 and the core 12 in a suitablemanner. The diameter of the casing 11 is adapted to the diameter of therelated passage 4,5, thus enabling the casing 11 to be inserted in thepassage 4,5 with a small clearance. Each of the cores 12 has two lugs14,15 projecting from the central portion and on each side thereof alongthe attachment piece's longitudinal axis 7.

Each of the lugs 14,15 has an abutment surface 16,17 extending at anangle, e.g. 90° relative to the rod's longitudinal axis, depending onthe reaction rod's position in the vehicle. These abutment surfaces formreference points, a functional length F of the reaction rod beingdefined as the distance between these reference surfaces of eachhousing. It will be appreciated that other locations of the attachmentpieces forming the reference points for the functional length may bechosen instead.

The lugs 14,15 have holes 18 and 19 respectively through which can bepassed respective bolts 20, which are indicated only by theirlongitudinal axis, for securing the attachment pieces 8,9 to a chassis21 and a wheel axle housing 22 respectively of the vehicle.

As illustrated in FIGS. 1,2 and 4, the rod 1 has two end portionsprovided as first connecting portions 31,32, and each of the housings2,3 has a second connecting portion 33,34, which is arranged to besecurely connected to the respective first connecting portions 31,32.

In the illustrated embodiment, each of the housings' second connectingportions 33,34 is in the form of a cylindrical tube which is splitpreferably in its longitudinal direction by a slot 37 at twodiametrically oppositely located points all the way to the respectivepassages 4,5, with the result that each housing has two cup-shapedportions or cups 35,36, which are semicircular in cross section anddefine a cylindrical space with a diameter corresponding to the rod'souter diameter. On account of this splitting, a certain amount ofelasticity is obtained, thus enabling the semicircular cups to be movedtowards or away from each other and be brought into close abutmentagainst the first connecting portions. Since the first and secondconnecting portions are in the form of an elongated cylindrical pin andan elongated, cylindrical hole respectively, the possibility is offeredof obtaining overlapping between the connecting portions in a simplemanner as well as the possibility of a relative axial movement of theconnecting portions before they are permanently interconnected.

During manufacture of the reaction rod, the attachment pieces 8,9, thehousings 2,3 and the rod 1 are fabricated separately. During thisprocess these parts do not need to be manufactured accurately in orderto achieve a functional length with a particularly fine tolerance.

For interconnection of the reaction rod's components, the pairs of cups35,36, i.e. the housings' second connecting portions 33,34 are pushed onto the rod's end portions, i.e. the first connecting portions 31,32. Theelasticity of the housings contributes hereby to an easy insertion ofthe first connecting portions 31,32. Furthermore, the attachment pieces8,9 are inserted in the respective passages of the housings with a smallclearance between them.

The attachment pieces 8,9 are then placed in a jig 50 (FIG. 5). The jig50 may, for example, have a bottom 51 on which is mounted a positioningdevice for the attachment pieces 8,9. This positioning device maycomprise four pillars or supporting portions 52,53,54,55, which projectup from the bottom 51, and against which the abutment surfaces 16,17 ofthe attachment pieces' lugs 14,15 can come into abutment. Thepositioning device may also comprise tension means such as four tensionblocks 56,57,58,59, which may be mounted on the opposite side of thelugs relative to the abutment surfaces 16,17, and which by means of,e.g. screws can be pulled towards the respective pillars 52-55, therebypressing the attachment pieces against them. The screws are representedin FIG. 5 only by a centre line 60 for one of them. The attachmentpieces can thereby be secured in such a manner that the relativedistance between their opposite abutment surfaces 16,17 exactlycorresponds to the functional length F with the desired tolerance, withthe rod 1 and the housings 2,3 able hereby to slide axially relative toeach other and permit securing of the attachment pieces.

The housings 2,3 are then connected securely, i.e. rigidly with the rod1 and the attachment pieces 8,9 connected securely with the housings 2,3by means of a suitable means of attachment, e.g. by welding, soldering,adhesion, etc. This kind of secure or rigid connection of the attachmentpieces with the housings provides a reinforcement of the housings. Ifwelding is employed, a number of holes 40 can be provided in the secondconnecting portions of the housing for interconnection of the housingsand the rod by plug welding.

If the housings are attached to the rod in a manner whereby there is arisk that the attachment pieces' rubber element can be damaged, e.g. byexcessive heating, there may be provided in the passages and between thehousings and the attachment pieces a sleeve-shaped lining 41 (FIG. 4)which is attached thereto, e.g. by means of an adhesive, therebyproviding better heat insulation of the rubber element. In addition thesleeve can cover a possible opening facing radially inwards in thepassage and defined by the cups 35,36 and the end of the rod, providinga reinforcement of the reaction rod at this point.

Since the attachment pieces do not have press fit relative to thepassages, less strain is placed on the above-mentioned transitionportion between the passages and the second connecting portions of thehousings. The housings can therefore be produced by stamping, bendingand/or pressing of a plate-shaped material, e.g. into the shapeillustrated in the figures, and the weight of the housings can besubstantially reduced. As illustrated, e.g., in FIG. 4, the housings'second connecting portions 33 can be composed of the two cups or halves35,36, which after a stamping process form end portions thereof andextend at a great distance apart, but which after a bending of the plateto approximately a C-shape, extend near each other with only the smallopening or gap 37. A housing of this kind made from a plate can comprisestamped or pressed portions which increase the rigidity of the housing.Even though these halves 35,36 in an uninfluenced state should define acylindrical space with a diameter that is smaller than the diameter ofthe first connecting portions 31, the halves can be moved slightly awayfrom each other, thus increasing the gap 37 due to the housing'selasticity, and permit reception of a first connecting portion 31. Byassembling the reaction rod's components in the above-mentioned manner,the production can be considerably simplified and much less expensive.By means of the invention, therefore, a cheap, light-weight reaction rodis also provided which reduces the unsprung weight of the vehicle.

The casing of the attachment pieces and the housings can advantageouslybe provided with a relative clearance, thus enabling the attachmentpieces to be displaced at an angle to each other when they have beenmounted in the jig. Alternatively or in addition the connecting portionscan be provided with such a clearance. By securing the attachment piecescorrectly in the jig and using an attachment means that advantageouslycompletely fills the clearances, e.g. an adhesive such as hardenableplastic, or a soldering agent, it can be ensured that the longitudinalaxes 7 of the passages 4 extend parallel to each other and at thecorrect angle relative to the rod's longitudinal axis 6 in the finishedreaction rod, e.g. perpendicular to the rod's longitudinal axis 6, inaddition to which the reaction rod's components are securelyinterconnected and the length of the reaction rod is correct.

With the above-mentioned method there may be a risk of damage to therubber element 13 if the housings 3,4 are attached to the rod 1 bywelding.

In order to avoid damage of this kind, the method of manufacturing therod can be as above with the following additional remarks, referencealso being made here to FIG. 6.

The through-going passage 4,5 has a first longitudinal axis L1 extendingthrough a centre point of the passage's cross section.

The two attachment pieces 8,9 have a second longitudinal axis L2extending through a centre point of the attachment pieces' crosssection.

The rod 1 and the housings 2,3 are assembled initially without beingpermanently interconnected. Initially, the attachment pieces 8,9 are notinserted in the passages 4,5.

The contour of each attachment piece is initially established in thedirection of the second longitudinal axis L2 as indicated by the arrowA. For this purpose use may be made, for example, of a digital camera 70connected to a computer 71.

Alternatively, mechanical sensors or the like may be employed which aresimilarly connected to the computer 71.

The contour is analysed in the computer 71 in order to establish thelocation of the centre point of the attachment pieces' contour, thecomputer 71 having a program that is suitable for this purpose.

The computer 71 then calculates the distance a between each attachmentpiece's 8,9 reference point 16,17 and centre point, considered in thedirection of the attachment piece 8,9 which coincides with the finishedreaction rod's longitudinal direction. The rod 1 with the housings 2,3is then mounted in a jig 72 with two parallel insertion pieces 73,74,whose cross section is adapted to the cross section of the passages 4,5,and each of which has third longitudinal axes L3 extending through thecentre point of the respective insertion pieces' cross section, theinsertion pieces 73,74 being inserted in the respective passages 4,5.The insertion pieces 73,74 may be conical and inserted in the passagesuntil they just touch the passage walls.

The distance between the third longitudinal axes L3 of the insertionpieces in the housings is then adjusted by means of an actuator 75,which is arranged to move relatively telescopically connected portions76,77 of the jig in relation to each other in such a manner that thedistance between the third longitudinal axes L3 corresponds to thedistance between the second longitudinal axes L2 when the referencepoints are at a relative distance corresponding to the functional lengthF. The actuator 75 is advantageously connected to the computer 71, thusenabling analysis values from the optical measurement concerning thedistance a to directly influence a movement of the jig's insertionpieces 73,74.

The housings 2,3 are then connected with the rod 1 and the attachmentpieces 8,9 are finally inserted in the respective passages 4,5 wherethey are fixed, for example, by means of an adhesive.

1. A method for manufacturing a reaction rod for use in connecting achassis (21) of a vehicle with a wheel axle housing (22) of the vehicle,where the reaction rod comprises a rod-shaped central portion or rod (1)with two end portions, each with its first connecting portion (31,32),two housings (2,3), each with its second connecting portion (33,34),which can be rigidly connected with the respective, first connectingportions (31,32), and each housing (2,3) has a through-going passage(4,5), and two attachment pieces (8,9), each of which extends throughits passage (4,5), and which on use of the reaction rod can be attachedto the chassis (21) and the wheel axle housing (22) respectively, wherethe distance between reference points (16,17) of the respectiveattachment pieces (8,9) establishes a functional length (F) of thereaction rod, where the rod (1) and the housings (2,3) are initiallyassembled without being permanently interconnected, and the attachmentpieces (8,9) are inserted in the respective housings (2,3),characterised by the following steps; mounting the rod (1) and theattachment pieces (8,9) in a jig (50) with a positioning device (52-60)thereby securing the attachment pieces (8,9), the distance between thereference points (16,19) corresponding to the functional length (F), andattaching the housings (2,3) to the rod (1).
 2. A method according toclaim 1, characterised by inserting a heat-insulating lining (41) in thepassages (4,5) between the housings (2,3) and the attachment pieces(8,9), and attaching the lining rigidly thereto.
 3. A method accordingto claim 1 or 2, characterised by providing the attachment pieces (8,9)and the respective passages (4,5) and possibly the first and secondconnecting portions (31,32) with a relative clearance that is such as topermit a relative angular displacement of these components in order toachieve a correct relative position of the components, and subsequentlyto fill the clearance with a fixing means in order to secure thecomponents in this position.
 4. A method according to one of thepreceding claims, characterised by manufacturing the housings (8,9) bystamping, bending and possibly pressing of a plate-shaped material.
 5. Areaction rod for use in connecting a chassis (21) of a vehicle with awheel axle housing (22) of the vehicle, where the reaction rod comprisesa rod-shaped central portion or rod (1) with two end portions, each withits first connecting portion (31,32), two housings (2,3), which havebeen fabricated separately from the rod (1), each with its secondconnecting portion (33,34), and which are rigidly connected with therespective, first connecting portions (31,32), and each housing (2,3)has a through-going passage (4,5), characterised in that the housingsare manufactured by stamping and bending of a plate-shaped material. 6.A reaction rod according to claim 5, characterised in that each housingis provided as a C-shaped hoop, the second connecting portion (33)comprising two halves (33 a,33 b) extending with a relative clearance(33 c).
 7. A jig for manufacturing a reaction rod for use in connectinga chassis (21) of a vehicle with a wheel axle housing (22) of thevehicle, where the reaction rod comprises a rod-shaped central portionor rod (1) with two end portions, each with its first connecting portion(31,32), two housings (2,3), each with its second connecting portion(33,34), which can be rigidly connected with the respective, firstconnecting portions (31,32), and each housing (2,3) has a through-goingpassage (4,5), and two attachment pieces (8,9), each of which extendsthrough its passage (4,5), and has attachment lugs (14,15), which on useof the reaction rod can be attached to the chassis (21) and the wheelaxle housing (22) respectively, where the distance between referencepoints (16,17) of the respective attachment lugs (14,15) establishes afunctional length (F) of the reaction rod, where the rod (1) and thehousings (2,3) are initially assembled without being permanentlyinterconnected, and the attachment pieces (8,9) are inserted in therespective housings (2,3), characterised in that the jig (50) comprisesa bottom (51) on which is mounted with an intermediate space apositioning device (52-55) for securing the respective attachment lugs(14,15), whereby the reference points (16,17) are kept at a relativedistance corresponding to the functional length (F), and the rod (1) andthe housings (2,3) can be attached to each other while thus secured. 8.A method for manufacturing a reaction rod for use in connecting achassis (21) of a vehicle with a wheel axle housing (22) of the vehicle,where the reaction rod comprises a rod-shaped central portion or rod (1)with two end portions, each with its first connecting portion (31,32),two housings (2,3), each with its second connecting portion (33,34),which can be rigidly connected with the respective, first connectingportions (31,32), and each housing (2,3) has a through-going passage(4,5) with a first longitudinal axis (L1) extending through a centralpoint of the passage's cross section, and two attachment pieces (8,9),each of which extends through its passage (4,5), and which on use of thereaction rod can be attached to the chassis (21) and the wheel axlehousing (22) respectively, where the attachment pieces (8,9) have asecond longitudinal axis (L2) extending through a centre point of theattachment pieces' cross section, where the distance between thereference points (16,17) of the respective attachment pieces (8,9)establishes a functional length (F) of the reaction rod, where the rod(1) and the housings (2,3) are initially assembled without beingpermanently interconnected, characterised by the following steps;establishing the contour of each attachment piece (8,9) in the directionof the second longitudinal axis (L2), analysing the contour of theattachment piece (8,9) and establishing the location of the centre pointof the contour, calculating the distance between the attachment piece's(8,9) reference point (16,17) and centre point, considered in thedirection of the attachment piece (8,9) which coincides with thefinished reaction rod's longitudinal direction, mounting the rod (1)with the housings (2,3) in a jig with two insertion pieces, whose crosssection is adapted to the cross section of the passages, and each ofwhich has third longitudinal axes (L3), extending through the centrepoint of the respective insertion pieces' cross section, the insertionpieces being inserted in the respective passages, adjusting the distancebetween the third longitudinal axes (L3) of the insertion pieces in thehousings in such a manner that the distance between the thirdlongitudinal axes (L3) corresponds to the distance between the secondlongitudinal axes (L2) when the reference points are at a relativedistance corresponding to the functional length (F), connecting thehousings with the rod, and inserting the attachment pieces in therespective passages.